Laser cladding by powder metal injection is used in manufacturing, component repair, rapid prototyping and coating. A laser beam travels down a passage to exit out a port in focused alignment with a flow of powdered metal, typically a conical flow around the laser. The laser melts both a thin layer of a surface of a part and the metal powder introduced to the surface, allowing the molten powdered metal to fuse with the surface of the part. This technique is well known for producing parts with enhanced metallurgical qualities such as a superior coating with reduced distortion and enhanced surface quality. Layers of various thicknesses can be formed on the part using laser cladding with the general range being 0.1 to 2.0 mm in a single pass.
Known nozzles for laser cladding have various levels of complexity. A common type is based on a concentric design with the laser beam passing through the center of the nozzle. Surrounding the central laser beam are concentric ports that may be formed as an annulus or continuous ring, segments of rings, or holes which deliver an inert shield inert gas, the powdered metal carried by an inert gas, and in some cases an outer shaping gas. However, such known nozzles for laser cladding assemblies are limited in that the majority of the gas flow is deflected away from the laser weld zone. Therefore a significant amount of the powdered metal directed at the weld zone actually escapes the process altogether. It would be desirable to provide a laser cladding device where the amount of powdered metal delivered to the laser welding zone and therefore to the part is increased.